Thermal storage system

ABSTRACT

The invention relates to a thermal storage system for storing thermal energy, comprising a solid storage which comprises a plurality of storage blocks with their outer sides arranged relative to one another, wherein the storage blocks comprise at least one continuous opening arranged in the longitudinal direction and/or at least one recess formed in the longitudinal direction at their outer side, and are arranged relative to one another such that at least one channel comprising an inlet opening and an outlet opening spaced apart from the inlet opening is formed by the recess and/or the continuous opening, a heat-carrying medium which is at least in portions in direct contact with the channel, a charging circuit comprising a first supply means connected to the inlet opening of the channel for supplying thermally charged heat-carrying medium and a first draining means connected to the outlet opening and/or a discharge circuit comprising a second draining means connected to the inlet opening of the channel for draining the thermally charged heat-carrying medium, and a second supply means connected to the outlet opening for compensating the drained heat-carrying medium.

TECHNICAL FIELD

The invention relates to a thermal storage system for storing thermal energy, the use of a thermal storage system for storing thermal energy and a method for storing thermal energy.

BACKGROUND OF THE INVENTION

In the course of the world's dwindling raw materials for energy production, the generation of renewable energy becomes increasingly important. For example, solar power plants can generate heat from solar power and feed it to a power plant for generating electricity. The energy production from solar power is coupled with the solar radiation and is therefore subject to strong fluctuations. At particularly sunny times, energy production from solar power can exceed the energy demand, while during cloudy times or during the night, only little or no energy can be produced by the solar power plant. Thus, there is a need to store excess energy from solar power plants, so that this energy can be used at a later time.

A device and system for temporarily storing thermal energy is known, for example, from DE 10 2009 060911 A1. The device comprises a solid storage and a piping system which is formed by individual pipes and extends through the solid storage, wherein an energy carrier medium flows through the piping system. In order to be able to charge and discharge the solid storage quickly and evenly with thermal energy, heat-conducting elements are provided which each form heat transfer areas with the individual pipes and which extend into the regions of the solid storage which are free of the individual pipes.

In this case, the heat-conducting elements have a higher thermal conductivity than the solid storage.

There is a steady need to optimize thermal storage systems in order to reduce manufacturing costs and increase the thermal storage efficiency.

DESCRIPTION OF THE INVENTION

It is the object of the invention to provide a thermal storage system for storing thermal energy, which can be produced economically and by means of which thermal energy can be stored in a simple manner.

The object is achieved by a thermal storage system, by use of a thermal storage system and by a method of storing thermal energy according to the features of the independent claims. Preferred embodiments of the invention are set forth in the dependent claims and in the following description which individually or in any combination may represent an aspect of the invention.

According to the invention, a thermal storage system for storing thermal energy is provided, comprising a solid storage including a plurality of storage blocks with their outer sides disposed relative to each other, wherein the storage blocks comprise at least one continuous opening arranged in the longitudinal direction and/or at least one recess formed in the longitudinal direction on its outer side and are arranged relative to each other so that the recess and/or the continuous opening form at least one channel with an inlet opening and an outlet opening formed spaced apart from the inlet opening, a heat-carrying medium which is at least in portions in direct contact with the channel, a charging circuit comprising a first supply means connected to the inlet opening of the channel for supplying thermally charged heat-carrying medium and a first draining means connected to the outlet opening for compensating the supplied heat-carrying medium, and/or a discharge circuit comprising a first draining means connected to the inlet opening of the channel for draining the thermally charged heat-carrying medium, and a second supply means connected to the outlet opening for compensating the drained heat-carrying medium.

Thermal energy preferably means solar thermic heat energy produced from a solar power plant and/or a solar power station and/or thermal waste heat from the industry and/or other available waste heat or thermal energy.

A recess is a channeling, groove, gutter and/or notch formed in the outer surface of a storage block in a longitudinal direction.

The continuous opening is preferably a continuous recess. Particularly preferably, the continuous opening of a storage block forms a channel section, so that the channel is formed by arranging a plurality of storage blocks relative to one another. Particularly preferably, the continuous opening is formed circular in a plane perpendicular to the longitudinal direction of the channel and/or the channel section.

The longitudinal direction of the recess and/or the continuous opening is preferably configured rectilinear. In this way, preferably center stones and/or end stones forming the inlet opening and/or the outlet opening of the solid storage are provided. Particularly preferably, the longitudinal direction has a curvature, wherein the curvature may be particularly preferably formed arcuate, quarter-circular and/or semicircular. In this way, end stones of the solid storage can be provided.

As heat-carrying medium basically any heat-carrying medium suitable for transferring heat is suitable. Preferably, the heat-carrying medium is water and/or water vapor that is preferably supplied under high pressure to the channel of the solid storage. The heat-carrying medium is particularly preferably air and/or tin, wherein tin has particularly advantageous thermal properties for transferring thermal energy.

The term “connected” in connection with the supply means and/or the draining means of the charging circuit and/or the discharge circuit is to be understood as a connection that allows transfer of the heat-carrying medium.

The thermal storage system thus comprises a solid storage which is formed by a plurality of storage blocks arranged relative to each other. The storage blocks have a recess formed in the longitudinal direction and/or a continuous opening, wherein the storage blocks are arranged relative to one another such that a channel with an inlet opening and an outlet opening is formed by the recess formed in the storage blocks and/or the continuous opening. The thermal storage system also comprises a charging circuit for thermally charging the solid storage and a discharge circuit for thermally discharging the solid storage. The charging circuit comprises a first supply means connected to the first inlet opening of the channel for supplying a thermally charged heat-carrying medium, preferably from a solar power plant, and a first draining means connected to the outlet opening for compensating the supplied heat-carrying medium. Thus, a thermally charged, i.e. heated and/or warmed up heat-carrying medium, is supplied to the solid storage via the inlet opening. In order to compensate for the supplied thermally charged heat-carrying medium, thermally discharged heat-carrying medium, i.e. heat-carrying medium that has transferred heat to the storage blocks, is drained through the outlet opening from the solid storage and preferably supplied to the solar power plant for renewed thermal charging. The discharge circuit comprises a second draining means connected to the inlet opening of the channel for draining the thermally charged heat-carrying medium, i.e. heat-carrying medium, which was preferably warmed up and/or heated by the previously thermally charged storage blocks, from the solid storage, so that the drained thermally charged heat-carrying medium can be supplied to a power plant or a power plant device for generating electricity. In order to compensate for the thermally charged heat-carrying medium drained from the solid storage, thermally discharged heat-carrying medium, i.e. heat-carrying medium, which has transferred heat for energy production in the power plant, is supplied to the channel via the outlet opening. In this way, a piping-free solid storage is provided, which can be thermally charged and thermally discharged in a simple manner. Due to the fact that the solid storage is formed piping-free, the manufacturing costs of the storage can be reduced. Due to the piping-free design of the solid storage, the heat-carrying medium is in direct contact with the storage block, so that heat transfer losses can be reduced and thus the efficiency of the thermal storage system can be increased.

Basically, the storage blocks may be formed differently from each other. In a preferred embodiment of the invention, it is provided that the storage blocks have a first end face and a second end face arranged spaced apart from the first end face in the longitudinal direction of a storage block, and the outer sides between the first end face and the second end face are formed parallel to the longitudinal direction of the storage block, wherein the first outer side is parallel and spaced apart from the second outer side and the third outer side is parallel and spaced apart from the fourth outer side. In this way, the storage blocks are formed cuboid so that the storage blocks can be arranged in a simple manner relative to each other.

In a preferred embodiment of the invention it is provided that a recess is formed in a corner region between the first outer side and the third outer side and/or in a corner region between the first outer side and the fourth outer side and/or in the second outer side. If the recess is formed in the corner region between the first outer side and the third outer side and/or between the first outer side and the fourth outer side, the recess is preferably formed as a rectilinear groove which preferably has a quarter-circular profile in a plane perpendicular to the longitudinal direction of the storage block. The recess at the fourth side is preferably designed as a rectilinear groove which preferably has a semicircular profile in a plane perpendicular to the longitudinal direction of the storage block. In this way, a channel can be formed in a simple manner by arranging a plurality of storage blocks.

An advantageous embodiment of the invention is that the continuous opening extends from the first end face through the storage block up to the second end face. In this way, a storage block is provided which preferably has a rectilinear continuous opening. Thus, preferably center stones or storage blocks are provided which are arranged in the center of the solid storage. Particularly preferably, it is provided that the continuous opening which extends from the first end face or the second end face through the storage block opens into one of the outer sides of the storage block. In this way, the continuous opening preferably has a curvature. This is particularly suitable for endstones or storage blocks which are arranged at the end of the solid storage. The respective continuous opening of a storage block forms a channel portion of the channel.

According to a preferred embodiment of the invention it is provided that the storage blocks comprise first connection elements on the first end face and/or first connection receptacles corresponding to the first connection elements on the second end face. In this way, the storage blocks can preferably be form-fittingly connected to each other in the longitudinal direction.

In this context, a preferred embodiment of the invention provides that the first connection elements are a dovetail connection and the first connection receptacles have corresponding tines. In this way, a first storage block comprising the first end face having the dovetail connection can be arranged in a form-fitting manner at the second end face of a second storage block comprising the tines. Thus, preferably a tensile strength connection between the storage blocks directed in the longitudinal direction of the channel can be provided.

In this context, a preferred embodiment of the invention provides that the dovetail connection and/or the tines are formed tapered starting from the second outer side in the direction of the first outer side. In this way, the insertion of the dovetail connection into the corresponding tines for connecting the storage blocks can be simplified whereby time and costs in the production of the solid storage can be reduced.

In principle, the outer sides of the storage blocks can be configured flat, so that in a plurality of storage blocks arranged relative to each other the outer sides can be butt joined. A preferred embodiment of the invention is that the storage blocks have second connection elements on the second outer side and/or second connection receptacles corresponding to the second connection elements on the first outer side. It is preferably provided that the second connection elements are one or more projections which are particularly preferably cylindrical and/or cuboid and are aligned in a direction perpendicular to the plane of the second outer side. The second connection receptacles are recesses which correspond to the projections of the second outer side and are particularly preferably aligned in a direction perpendicular to the plane of the first outer side. In this way, the first outer side of a first storage block can be connected in a simple manner to the second outer side of a second storage block in a form-fitting manner.

An advantageous embodiment is that the butt joints of the storage blocks are bonded. In this way, the storage blocks can be materially connected to one another. In addition, the butt joints can be sealed so that no heat-carrying medium can escape via the butt joints. Particularly preferably, the bonding of the butt joints of the respective storage blocks is done via a high temperature adhesive which has a temperature resistance of greater than 400° C., preferably greater than 700° C. and most preferably greater than 1000° C.

According to a preferred embodiment of the invention it is provided that the storage blocks are arranged offset from each other. In this way, the structural integrity of the solid storage can be increased.

An advantageous embodiment of the invention is that the storage blocks are arranged relative to each other so that the first channel is formed meandering. In this way, the channel length within the solid storage for the thermal charging of the solid storage can be increased. In addition, the inlet opening and the outlet opening can thus be formed on one side of the solid storage. If the inlet opening and the outlet opening are formed on one side of the solid storage, the side of the solid storage which comprises the inlet opening and the outlet opening can preferably have a fixed bearing, wherein the part of the solid storage which comprises the channel has a sliding bearing. Thermal changes in length of the solid storage are not hindered by the sliding bearing. Thus, the charging circuit and/or discharge circuit connected to the inlet opening and/or the outlet opening can be decoupled from the thermally induced changes in length of the solid storage in the course of the thermal charging and/or discharge. In this way, the manufacturing costs of the thermal storage system can be reduced.

In an advantageous embodiment of the invention it is provided that a valve device is provided upstream of the inlet opening and/or the outlet opening. Preferably, the valve device is periodically controllable. In this way, it can be controlled that in a first period thermally charged heat-carrying medium is supplied via the first supply means and via the inlet opening from a solar power plant to the channel for thermal charging the storage blocks and in a second period thermally charged heat-carrying medium is drained from the thermal storage via the inlet opening and via the second draining means and supplied to a power plant for generating electricity. Thus, charging and discharging of the solid storage can take place with only one channel. A reduced number of channels or only one channel can increase the structural integrity of the solid storage.

A preferred embodiment of the invention provides that the charging circuit and/or the discharge circuit comprises a heat exchanger. If the heat exchanger is arranged in the charging circuit, thermal heat generated in the solar power plant is preferably transferred in the heat exchanger to the heat-carrying medium and then supplied to the solid storage for storage. Heat-carrying medium supplied from the solid storage via the outlet opening in the direction of the solar power plant is likewise supplied to the heat exchanger. In this way, in the solar power plant a heat-carrying medium different from that of the thermal storage system can be used. The same applies to the discharge circuit.

Basically, only one channel is sufficient for the thermal charging and discharging of the solid storage. In a preferred embodiment of the invention, it is provided that the solid storage has a plurality of channels.

In this context, a preferred embodiment of the invention provides that in the case of the plurality of channels a first channel is the charging circuit and a second channel is the discharging circuit. In this way, the charging circuit and the discharging circuit are channel-technically separated, so that parallel or simultaneously with the thermal charging, a thermal discharge can take place.

The storage blocks can in principle be made of any material for storing thermal energy. Preferably, the storage blocks are made of a concrete. In a preferred embodiment of the invention it is provided that the storage blocks are made of fly ash, preferably made of ceramically fired fly ash. For this purpose, preferably fly ash, water and organic additives are mixed, so that the resulting matrix has a plastic property. The plastic matrix is filled under pressure into molds, removed from the mold and fed to an oven. At a temperature between 1,000° C. and 1,200° C. the fly ash sinters and individual globules of the fly ash melt with their surroundings and form a firm bonding. Alternatively or in addition, it is provided that the storage blocks are made of blast-furnace slag, preferably of ceramically fired blast-furnace slag. Blast furnace slag is formed during iron smelting and is tapped from the blast furnace as waste product at a temperature of more than 1,600° C. The slag is poured into molds to form the storage blocks and solidified. Furthermore, already tapped and solidified blast furnace slag can be granulated and fed to a ceramic processing for forming the storage blocks. Fly ash and/or blast furnace slag are understood within the scope of the invention to be any mineral residues from combustion processes and metal production processes, for example, boiler sand, coarse ash, clinker or electric furnace slag.

A preferred embodiment of the invention provides that the solid storage is arranged in a housing, wherein the housing preferably has a thermal insulation. In this way, heat losses of the solid storage can be reduced.

In an advantageous embodiment of the invention, the storage blocks comprise first and/or second connection elements embedded in the storage blocks at the inlet opening and at the outlet opening which are configured form-fittingly with the channel and extend the channel outside of the storage blocks to connect the form-fitting contact with the heat-carrying medium and the first and/or second connection element of the next storage block.

A preferred embodiment of the invention provides that the first and/or second connection elements are made of a temperature resistant steel, which has been previously processed by form-giving processes, and/or wherein a connection between first and/or second connection elements of two storage blocks which are in contact with each other are configured as welded and/or screwed connection. Preferably protruding first and/or second connection elements are sheathed with sleeves, which fit form-fittingly between adjacent storage blocks around the first and/or second connection elements in order to store more energy and to insulate the first and/or second connection elements. In this context, it is further preferred that the sleeves are designed to supplement an outer shape of the storage blocks, in particular a geometry, such that a continuous shaping over a plurality of storage blocks and first and/or second connection elements is obtained.

The invention further relates to the use of a thermal storage system comprising a solid storage including a plurality of storage blocks which are disposed with their outer sides relative to each other, wherein the storage blocks comprise at least one continuous opening arranged in the longitudinal direction and/or at least one recess formed in the longitudinal direction on their outer side, and are arranged relative to each other so that at least one channel comprising an inlet opening and an outlet opening spaced apart from the inlet opening is formed by the recess and/or the continuous opening, a heat-carrying medium at least partially in direct contact with the channel, a charging circuit comprising a first supply means connected to the inlet opening of the channel for supplying thermally charged heat-carrying medium and a draining means connected to the first outlet opening for compensating the supplied heat-carrying medium, and/or a first discharge circuit connected to the inlet opening of the channel for draining the thermally charged heat-carrying medium, and a second supply means connected to the outlet opening for compensating the drained heat-carrying medium.

The invention also relates to a method for storing thermal energy, comprising the steps of: providing a thermal storage system comprising a solid storage having a plurality of storage blocks which are arranged with their outer sides relative to each other, wherein the storage blocks comprise at least one continuous opening disposed in the longitudinal direction and/or at least one recess formed on its outer side in the longitudinal direction, and are arranged relative to each other such that at least one channel comprising an inlet opening and an outlet opening formed spaced apart from the inlet opening is formed by the recess and/or the continuous opening, a heat-carrying medium which is at least in portions in direct contact with the channel, a charging circuit comprising a first supply means connected to the inlet opening of the channel for supplying thermally charged heat-carrying medium and a first draining means connected to the outlet opening for compensating the supplied heat-carrying medium, and/or a discharge circuit comprising a first draining means connected to the inlet opening of the channel for draining the thermally charged heat-carrying medium, and a second supply means connected to the outlet opening for compensating the drained heat-carrying medium, wherein for the thermally charging of the storage block via the charging circuit:

-   -   thermally heated heat-carrying medium is supplied via the inlet         opening to the channel, and     -   thermally discharged heat-carrying medium is drained via the         outlet opening, and for the thermal discharge of the storage         blocks via the discharge circuit:     -   thermally charged heat-carrying medium is drained via the inlet         opening, and     -   thermally discharged heat-carrying medium is supplied via the         outlet opening to the channel.

Finally, it is pointed out that the preferred and/or advantageous embodiments of the thermal storage system also apply to the use according to the invention and to the method according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained with reference to the accompanying drawings based on preferred exemplary embodiments by way of example, wherein the features shown below, both individually and in any combination, can represent an aspect of the invention. In the drawings:

FIG. 1 is a schematic representation of a thermal storage system according to a preferred exemplary embodiment of the invention;

FIG. 2 is a view of a storage block according to a first preferred exemplary embodiment of the invention;

FIG. 3 is a view of a plurality of storage blocks arranged offset from one another according to the first preferred exemplary embodiment of the invention; and

FIG. 4 is a view of a storage block according to a second preferred exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a schematic representation of the thermal storage system 10 for storing thermal energy. The thermal storage system 10 comprises a solid storage 12 with a plurality of storage blocks 14 disposed with their outer sides relative to each other. A detailed view of the storage blocks is given in FIGS. 2 to 4. The storage blocks 14 comprise a longitudinally extending continuous opening 16 and/or at least one longitudinally formed recess 18 on their outside and are arranged relative to one another such that a channel 20 comprising an inlet opening 22 and an outlet opening 24 formed spaced apart from the inlet opening 22 is formed by the recess 18 and/or the continuous opening 16. Furthermore, a second channel 26 different from the first channel 20 and comprising a second inlet opening 28 and a second outlet opening 30 disposed spaced apart from the second inlet opening 28 is formed by the storage blocks 14. In this way, a piping-free solid storage 12 is provided, whereby material and manufacturing costs of the thermal storage system 10 can be reduced.

The thermal storage system 10 also comprises a charging circuit 32 for thermally charging the solid storage 12 and a discharge circuit 34 for thermally discharging the solid storage 12.

The charging circuit 32 comprises a first supply means 36 for thermally charging the solid storage 12 by supplying a thermally charged heat-carrying medium and a first draining means 38 for compensating the supplied heat-carrying medium.

The first supply means 36 is connected via a first valve device 40 to the inlet opening 22 of the channel 20 and to the second inlet opening 28 of the second channel 26. At one end of the first supply means 36 which is facing away from the inlet opening 22 the first supply means 36 is connected to a solar power plant 42. In this way, a heat-carrying medium thermally charged by the solar power plant 42 can be supplied by the first supply means 36 via the inlet opening 22 to the channel 20 and via the second inlet opening 28 to the second channel 26 and thus to the solid storage 12 for thermally charging the storage blocks 14.

The first draining means 38 is connected to the outlet opening 24 of the channel 20 and to the second outlet opening 30 of the second channel 26 via a second valve device 44. The first draining means 38 is connected to the solar power plant 42 at one end of the first draining means 38 which faces away from the outlet opening. In this way, in order to compensate for the supplied thermally charged heat-carrying medium, thermally discharged heat-carrying medium can be drained from the solid storage 12 via the outlet opening 24 and the second outlet opening 30 and supplied to the solar power plant 42 for renewed thermal charging.

The discharge circuit 34 comprises a second draining means 46 for thermally discharging the solid storage 12 and a second supply means 48 for compensating the drained thermally charged heat-carrying medium.

The second draining means 46 is connected at one end via the first valve device 40 to the inlet opening 22 of the channel 20 and the second inlet opening 28 of the second channel 26 for draining the thermally charged heat-carrying medium from the solid storage 12. At one end of the second draining means 46 which faces away from the second inlet opening 28 the second draining means 46 is connected to a power plant 50 for generating electricity. In this way, the thermally charged heat-carrying medium can be supplied from the solid storage 12 to the power plant 50 for generating electricity.

The second supply means 48 is connected via the second valve device 44 to the outlet opening 24 of the channel 20 and to the second outlet opening 30 of the second channel 26. At one end of the second supply means which faces away from the second outlet opening 30 the second supply means 48 is connected to the power plant 50. In this way, in order to compensate for the thermally charged heat-carrying medium supplied to the power plant 50, thermally discharged heat-carrying medium can be supplied to the solid storage 12 via the outlet port 24 and the second outlet port 30 for renewed thermal charge.

Thus, a piping-free solid storage is provided, which can be thermally charged and thermally discharged in a simple manner. Due to the fact that the solid storage is configured piping-free, the manufacturing costs of the thermal storage system can be reduced. In addition, the heat-carrying medium is in direct contact with the storage blocks, so that heat transfer losses can be reduced.

The first valve device 40 and the second valve device 44 are each configured as a 4/2-way valve.

The thermal charging and the thermal discharge of the solid storage 12 are carried out periodically. In this way, the channel 20 and the second channel 26 can be used for thermal charging of the solid storage 12 and for thermal discharge, whereby the number of channels 20, 26 in the solid storage 12 can be reduced and the structural integrity of the solid storage 12 can be increased.

The plurality of storage blocks 14 are arranged so that the channel 20 and the second channel 26 extend in a meandering form. In this way, the inlet opening and the outlet opening of the channel 20 as well as the second inlet opening 28 and the second outlet opening 30 of the second channel 26 can be formed on one side of the solid storage 12, so that they can be easily connected via the corresponding supply means 36, 48 and draining means 38, 46. The side of the solid storage 12 comprising the inlet opening 22, 28 and the outlet opening 24, 30 is fixedly mounted or has a fixed bearing 51. The part of the solid storage 12, which comprises the channels 20, 26, is slidably mounted or has a sliding bearing 53. Thermally induced changes in length of the solid storage 12 are not hindered by the sliding bearing 53. In this way, the charging circuit 32 and/or the discharge circuit 34 can be decoupled from the thermally induced changes in length of the solid storage 12. Thus, manufacturing costs of the thermal storage system 10 can be reduced.

FIG. 2 shows a storage block 14 known from FIG. 1, wherein the solid storage 12 shown in FIG. 1 is formed from a plurality of storage blocks 14. The storage block 14 has a cuboid shape and comprises a first end face 52 and a second end face 56 arranged spaced apart from the first end face 52 in the longitudinal direction 54 of a storage block 14. The outer sides 58 are formed between the first end face 52 and the second end face 56 parallel to the longitudinal direction 54 of the storage block 14. The first outer side 60 is arranged parallel to and spaced apart from the second outer side 62. The third outer side 64 is parallel to and spaced apart from the fourth outer side 66.

In a corner region between the first outer side 60 and the third outer side 64, as well as in a corner region between the first outer side 60 and the fourth outer side 66 a respective recess 18 is formed in the longitudinal direction 54 of the storage block 14 as a rectilinear groove, which has a quarter-circular profile in a plane perpendicular to the longitudinal direction 54 of the storage block 14. At the second outer side 62, the recess 18 is formed in the form of a rectilinear groove which has a semicircular profile in a plane perpendicular to the longitudinal direction 54 of the storage block 14.

FIG. 3 shows a plurality of the storage blocks 14 known from FIG. 2, which are arranged offset from each other. A first storage block 14′ adjoins with its fourth outer side 66′ at least in sections to the third outer side 64″ of a second storage block 14″. A third storage block 14′″ is arranged at least in sections with its first outer side 60′″ at the second outer side 62′ of the first storage block 14′ and the second outer side 62″ of the second storage block 14″. The semicircular recess 18″ formed at the second outer side 62″ of the second storage block 14″ and the recess 18′″ formed in the corner region of the first outer side 60′″ and fourth outer side 66″ of the third storage block 14″ are arranged parallel to each other. In this way, by the arrangement of a further fourth storage block (not shown), which at least in sections adjoins to the fourth outer side 66′″ of the third storage block 14′″ and to the second outer side 62″ of the second storage block 14″, a channel 20 or a channel portion is formed.

FIG. 4 shows a second embodiment of the storage block 14, wherein the storage block 14 comprises an opening 16 which extends continuous from the first end face 52 to the second end face 56. The opening 16 need not necessarily extend from the first end face 52 to the second end face 56, but may also preferably open from the first end face 52 or the second end face 56 into one of the four outer sides.

The storage block 14 comprises first connection elements 74 formed as a dovetail connection 72 at the first end face 52, and first connection receptacles 78 corresponding to the first connection elements 74 and formed as tines 76 at the second end face 56. Thus, preferably, a tension-proof connection directed in the longitudinal direction of the channel 20 shown in FIG. 1 can be provided between the storage blocks 14.

Starting from the second outer side 62 in the direction of the first outer side 60, the dovetail connection 72 and the tines 76 extend tapering. In this way, the insertion of the dovetail connection 72 into the corresponding tines 76 for connecting the storage blocks 14 together can be simplified, whereby time and costs in the production of the solid storage 12 can be reduced.

At the second outer side 62 the storage block 14 comprises second connection elements 80 in the form of a plurality of projections formed cuboid in a direction perpendicular to the plane of the second outer side 62. At the first outer side 60 second connection receptacles 82 corresponding to the second connection elements 80 are arranged. The second connection receptacles 82 are preferably recesses aligned in a direction perpendicular to the plane of the first outer side 60 and corresponding to the projections of the second outer side 62. In this way, the first outer side 60 of a first storage block 14 can be connected in a simple way in a form-fitting manner to the second outer side 62 of a second storage block 14.

The exemplary embodiments described are merely examples which can be modified and/or supplemented in various ways within the scope of the claims. Each feature described for a particular exemplary embodiment may be used alone or in combination with other features in any other exemplary embodiment. Each feature described for an exemplary embodiment of a particular category may also be used equivalently in an exemplary embodiment of another category.

REFERENCE SYMBOLS

-   10 thermal storage system -   12 solid storage -   14 storage block -   16 continuous opening -   18 recess -   20 channel -   22 inlet opening -   24 outlet opening -   26 second channel -   28 second inlet opening -   30 second outlet opening -   32 charging circuit -   34 discharge circuit -   36 first supply means -   38 first draining means -   40 first valve device -   42 solar power plant -   44 second valve device -   46 second draining means -   48 second supply means -   50 power plant -   51 fixed bearing -   52 first end face -   53 sliding bearing -   54 longitudinal direction of storage block -   55 second end face -   58 outer sides -   60 first outer side -   62 second outer side -   64 third outer side -   66 fourth outer side -   72 dovetail connection -   74 first connection element -   76 tines -   78 first connection receptacles -   80 second connection elements -   82 second connection receptacles 

1. Thermal storage system for storing thermal energy, comprising a storage comprising a plurality of storage blocks with their outer sides arranged relative to each other, wherein the storage blocks comprise at least one continuous opening disposed in the longitudinal direction and/or at least one recess disposed in the longitudinal direction, and are arranged relative to each other so that at least one channel with an inlet opening and an outlet opening spaced apart from the inlet opening is formed by the recess and/or the continuous opening; a heat-carrying medium which is in direct contact at least in portions with the channel; a charging circuit comprising a first supply means connected to the inlet opening of the channel for supplying thermally charged heat-carrying medium and a first draining means connected to the outlet opening to compensate for the supplied heat-carrying medium; and/or a discharge circuit comprising a second draining means connected to the inlet port of the channel for draining the thermally charged heat-carrying medium, and a second supply means connected to the outlet opening to compensate for the drained heat-carrying medium, wherein the storage blocks are made of fly ash and/or blast furnace slag.
 2. Thermal storage system according to claim 1, wherein the storage blocks comprise a first end face and a second end face arranged in the longitudinal direction of a storage block and spaced apart from the first end face, the outer sides are formed between the first end face and the second end face parallel to the longitudinal direction, wherein the first outer side is formed parallel to and spaced apart from the second outer side and the third outer side is formed parallel to and spaced apart from the fourth outer side.
 3. Thermal storage system according to claim 2, wherein the recess is formed in a corner region between the first outer side and the third outer side and/or in a corner region between the first outer side and the fourth outer side and/or in the second outer side.
 4. Thermal storage system according to claim 1, wherein the storage blocks comprise first connection elements at the first end face and/or first connection receptacles corresponding to the first connection elements at the second end face.
 5. Thermal storage system according to claim 4, wherein the first connection elements are dovetail connections and the first connection receptacles are corresponding tines.
 6. Thermal storage system according to claim 1, wherein the storage blocks comprise second connection elements at the first outer side and/or second connection receptacles corresponding to the second connection elements at the second outer side.
 7. Thermal storage system according to claim 1, wherein the storage blocks are arranged relative to each other so that the channel is formed meandering.
 8. Thermal storage system according to claim 1, wherein a valve device is disposed upstream of the inlet opening and/or the outlet opening.
 9. Thermal storage system according to claim 1, wherein the storage blocks comprise first and/or second connection elements which are embedded in the storage blocks at the inlet opening and at the outlet opening and which are formed form-fittingly with the channel and extend this channel outside of the storage blocks in order to connect the form-fitting contact with the heat-carrying medium and the first and/or second connection element of the next storage block.
 10. Thermal storage system according to claim 1, wherein the first and/or second connection elements are made of a temperature-resistant steel, which has been previously processed by form-giving methods, and/or wherein a connection between first and/or second connection elements of two storage blocks which are in mutually contact is configured as a welded and/or screw connection.
 11. Thermal storage system according to claim 1, wherein protruding first and/or second connection elements are sheathed with sleeves, which fit form-fittingly between adjacent storage blocks (14) around the first and/or second connection elements in order to store additional energy and to insulate the first and/or second connection elements.
 12. Thermal storage system according to claim 11, wherein the sleeves are configured to supplement an outer shape of the storage blocks such that a continuous shaping over a plurality of storage blocks (14) and first and/or second connection elements is obtained.
 13. Use of a thermal storage system according to claim 1 for storing thermal energy.
 14. Method of storing thermal energy, comprising the steps of: providing a thermal storage system according to claim 1, wherein for thermal charging of the storage blocks via the charging circuit: thermally heated heat-carrying medium is supplied via the inlet opening to the channel; and thermally discharged heat-carrying medium is drained via the outlet opening from the channel; and for thermal discharging the storage blocks via the discharge circuit: thermally charged heat-carrying medium is drained via the inlet opening; and thermally discharged heat-carrying medium is supplied via the outlet opening to the channel. 